Spraying device for paints, varnishes, etc.



Oct. 11,1932. v w, HERMANN 1,881,569

SPRAYING DEVICE FOR' PAINTS, VARNISHES, ETC

Filed March 30, 1928 2 Sheets-Sheet l WIW 'HI M UWM .1M l immun' Oct. 11, 1932. w. HERMANN SPRAYING DEVICE Fon P AINT's ETC vARNIsans, Fied March so, 192e 2 Sheets-Sheet 2 y Patented oct. 11, 1932 UNITED STATES PATENT OFFICE WOLFGANG HERMANN, OF CHICAGO, ILLINOIS, ASSIGNOB TO. METAL SPECIALTIES MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS SPRAYING DEVICE FOR PAINTS, VABNISHES, ETC.

Application Med Iarch 30, 1828. Serial No. 285,867.

This invention relates particularly to varnish-spraying devices, but the invention may be ut tovarious analogous uses.v

he primary obj ect is to provide an efficient compact unit,which embodies a portable motorl and compressor of such compactness and efficiency as to enable the outfit to be carried.

by the operator while performing the spraying operation. l

The invention is illustrated in a referred embodiment in the accompanying rawings, vin which--A Fig. 1 is a view partly in side elevation and artl in section of a spraying deviceemodylng the invention; Fig. 2, a broken rearl end view of the motor; Fig. 3, a broken view taken as indicated at line 3 of Fig.1, the capplate of the rotary compressor being removed; Fig. 4, a sectional view taken as lndicated at line 4 of Fig.S 1, showing the inlet port of the compressor; Fig. 5, a view taken as indicated at line 5 of Fig. 1, and showing the outlet port. of the compressor; Fig. 6, av

broken verticaly sectional view taken as indicated at line 6 of Fig. 1; Fig. 7, a section through the nozzle taken as indicated at line 7 of Fig. 1; Fig. 8, a broken vertical sectional view of the lower portion of the handle, taken as indicated at line 8 of Fig. 1; Fig. 9, a

broken vertical sectional view of the compressor, slightly modied; Fig. 10, a section taken as indicated at line 10 of Fig. 9; Fig.

11, a broken sectional view showing details of the switch. device; Fig. .12, a section taken as indicated at line 12 of Fig. 11; and Fig. 13,.

a front view of the trigger-device.

In the construction illustrated, A designates a motor-compressor unit having a horizontal axis; B, ahandle supporting said unit; C, a nozzle extending forwardly from the unit A; and D, a can, or container, suspended from the nozzle.

The axis of the motor-compressor lies in the longitudinal vertical plane of the handle and nozzle.- i l The .motor-compressor unit Ais shown as comprising a motor-casing A containing an armature A2 equipped with a shaft-1; a skele-l ton cap-plate Aj forming one end of the motori-Casin and a rotary compressor A carried by tl e cap-plate A".

The motor-casing A is shown with a rounded rear end wall 2 which is shown provided with air-inlets 2 protected by wirefrom and support t e cylinder 5 of the ro-v tary compressor. The member A8 thus is a skeleton cap-plate having the cylinder of the compressor serving as the hub-portion of the spider. The cylinder has an inte al end- Wall 5n fr om which extends a bearing 5" for the shaft 1.

The skeleton cap-plate A3 of which the body of the compressor-casing forms a part may be of cast aluminum. In such case, it is preferred to insert in the cylinder a bottomplate 6 which may be of brass, or steel, and a sleeve 7 of similar material which forms a circumferential lining for the cylinder of the compressor.

The armature-shaft 1 is supported in a bearing-sleeve 8 within the member 5b.

The rotor of the compressor is designated 9. The rotor is disposed eccentrically with relation to the bore 10 ofthe compressorchamber. The shaft 1 is shown provided at its extremity with a transverse slot 11 which is engaged by a screw, .or pin, 12 with which the rotor is equipped. The rotor isof smaller diameter than the bore 10 of the compressorchamber, and the inner rWall of the sleeve 7 preferably is provided at one side with a concavity 7 having a curvature corresponding with the curvature of the rotor.

The rotor is provided with oblique slots 9 within which are located the sliding vanes 13.

The front end of the cylinder 5 is closed teriorly near its rear end.

. 21 of the nozzle is connected..

1 is provided at one side. with a longitudinal groove 1" through which lubricant may find its way to the rear side of the rotor. Preferably disks of felt 16are located 1n the lower portion vof the chamber and preferably the rotor 9 is provided with passages 17 extending therethrough parallel with the axis of the rotor and filled with felt. The felt sei-vesto absorb oil and to yield the same as needed. berv 1,5 prevents the oil from passing 'too quickly into the compressor-chamber.

The base-ring 4 of the capi-plate A3 1s secured by means of long cap-screws 18 to lugs 19 with which the casing A is provided in- The cap-piece 14 of the compressor is provided at its lower portion with a hollowtapped boss 20 with which the threaded shank The bottom wall- 5 'of the compressorchamber is provided (Eig. 4) with/an admission port 22 which admits air to the compressor. chamber is provided (Fig. 5) with an outletpassage 23 which leads to the passage 24 'which communicates rwith the bore of the nozzle.

The armature-shaft 1 is equipped back of the cap-plate A3. with a fan 25 which serves to draw air through thek screens 2b at the rear end-wall of the motor-casing and expel the same through the spaces between the radiator fins 4a, as indicated. by the arrows in Figl.

The handlel B is hollow. Its-upper end is shaped topform a cradle 26 which conforms tothe lower side of-the horizontally disposed motor-casing and which is secured to the motor-casing as by means of screws 27. vrllhe lower end-portion of the handle is equipped? with laterally extending arms 28 which terminate in feet 28aL adapted to rest upon a support. The' handle, in conjunction with the container D, is'adapted to support the spraying device in standing position on a table, for example. v

In the upperportion of the handle isfhoused a switch-device 29 which is mounted on an internal bracket 30 and which is equipped withfa. switch-lever 31 adapted to be actuated Current is supplied to the motor through conductors 34 and 35 which extend upwardly through the handle, the conductor 35 being divided and passing to the switch-points, so that when the switch is closed by actuating Ythetrigger l22, current will be supplied to the motor; and when the pressure of the The felt in the bottom'of the cham- The cap-plate 14 of the compressorv linger is released, the circuit will be automatically broken. v, v l

The nozzle C is shown as comprising an inner member 36, an outer tip-member 37, and a ring 38 interposed between the rear end of the member 37 and a shoulder 39. The ring 38 has depending therefrom a member 38 provided with a passage 38b which communicates with a tube 38 a pted to depend into the container They member 38 is provided with a flange 40 which is secured to a closure 41 with which the container D is equipped.

The inner member 36 of thnozzle is provided at one side with a longitudinal groove. or passa e, 42 which communicates with a space 43 etween the tip-portion of the inner member 36 and the outer member 37. The rear end of the groove 42 communicates with an annular passage 44which, in turn, communicates with the Huid-passage 38h, asshown in Fig. 6. The passage 38" is controlled by a needle-valve 45..

The bore 46 of thenozzle through which the. air passes to the tip ofthe nozzle is provided at its frontend with a reduced passage 46a. As the air isemitted through this reduced passage, the eiect is to cause a suction through. the passage 42 so that liquid will be drawn to the point of the nozzle.

The can D has its top equipped with a threaded nipple 47.which receives the cap 41 of the attaching device. /A gasket 48 serves to make an air-tight joint.

The-wires 34 and 35 lead into the .handle through a tubular boss 49 which is equipped wit-h a iiexible extension (close coiled Wire) 50. The wires 34 and 35 form a part of a cord 51 which is equipped with a connector member 51a.

i The details of the switch-device 29 willv be understood from Figs. 11 and 12. AEmbedded and securely housed between insulation-laminations 52 of a switch-block are a palr of spaced contacts 53 and 54 having coutact segments 53a and 54El which are exposed ina chamber 55 formed by recessing the insulation-strips. t

A met-al roller 56 is adapted to travel back and forth along the arched top of the chamber 55 and in one position to bridge the space between the contact-points 53a and 54a and close the circuit. The switch-block is mounted upon a U-shape sheet-metalbase 57 which v is equipped with a threaded tubular nipple 571l which extends through a hole in the bracket 30 and is-secured by means of thin clamp-v ing-nuts 58. l

The switch-lever 31 is supported on a pivot 59 carried by the member 57,A It

has a central ball-portion 6 0 located within the tubular member 57a.

sleeve 61 which may be of rubber, or felt, is

-interposed between the ball-portion and the tubular member 57, making a gas-tight connection, without interfering with the working of the trigger. The ujrpose 1s .to prevent inflammable gases rom reachmg the switch-points.

` The bracket 30 is carried by a trigger-plate 62 which is secured by means of screws 68 .to

bosses 64 with which the front upper portlonJ of the handle Bis provided.

The handle B may be of cast aluminum. As shown in Fig. 8, the front upper portlon ofjthe `/handle is furcated, or provided witha slot 65 to permit the insertion of the trigger device. l

The inner end-portion ofthe switch-lever 31'an'd a member 66 which engages the roller 56 to form a sort of to le-lever are adapted to actuate the roller. gghe member 66 has a slotted stem 66 which forms a uide for a dished disk 67 which is backed y a spring 68. The inner end of the lever 31l is adapted to work within the slotted stem. When the lever 31 is actuated by pressing the triger 32 rearwardly, the member 66 is swung orwardly about the roller 56 as a pivot, and, passing the dead center, forces the roller to travel rearwardly into contact with the contact-points 53',L and 54, thus closing the circuit. Upon the release. of the trigger, the spring 33 returns the parts to the circuitbreaking position.

It has been found in practice that as soon as the circuit is broken, liquid will no longer be drawn from the container D; hence, it is unnecessary' to employ a valve controlling the li uid passage. f l

`llt e operation of the improved spraying device, the device is held in the hand of the operator like a pistol. The weight of the motor and compressor unit, the nozzle, vand the container are properly distributed with relation to the handle so that the. device can be supported at arms length, or partially so, without too great eiort. y

It will be noted that the longitudinal 'axis of the motor which corresponds with the axiso the armature-shaft points forwardly at a position above the hand of the operator,

and the compressor is connected with the front end of the armature-shaft in position to deliver compressedair directly mto the nozzlef. The rotary compressor is directcou led to the armature and rotates at very hig speed, so that a small compressor is thus capable of delivering fairly high presure, say ten to twenty pounds per square inch.

In the circulation of the air which occurs in the operation of the device, there is some danger that inflammable gases-may reach the commutatorv of the motor o f the contactpoints of the switch device. To guard against possible explosion, 'protecting features have been incorporated, as described above.

In the operation of the compressor, a considerable amount of heat is developed. This heat is dissipated by currents of air driven by the fan 25 through the 'spaces between the radiator-fins 4e..

vIn the oilin system `provdided for the compressor," 1u ricant `is first 'conducted to the central ortion of the rotor and is thrown outwardl y centrifugal action, reaching all parts'. T e blades, or vanes, 13 preferablyare formed of hard fibre, but may be of an suitable material. fflhey do not require t elfuse of springs t( \.maintain them in contact withm the lnner wall of the' compressorcylinder.

The rotor preferably has a very slight clearance at the point of contact with the concavity 7, suilicient to permit an exceedingly thin oil film to form between the surfaces. Thus the rotor may be in a sense regarded as a oating rotor.

In the modificationshown inj Figs. 9- and 10, the construction corresponds with the construction heretofore described, except that the armature-shaft 1 is shortened and is coupled to a separate/extension l upon which the rotor is mounted. Thus, the rotor has an individual shaft l", and thisepreferably is coupled to the shaft 1 by means of a key lc which engages a slot 1d. In this modification, both ends of the shaft-extension 1b 'are journalled in bearings 69, one of which is in the bottom-plate 6, and the other of which is in the cap-plate 14 of the compressorchamber.`

The improved device is thoroughly adapted to its purpose. It has a largefield of use for many purposes and in many situations where the large and expensive compressed-air `supplying devices are not available. `vThe organization Kof mechanisms and parts disclosed is such' as to enable a self-contained, hand-carried spraying device, or unit, comprising a motor, compressor and nozzle to be used with the greatestpracticability.

A modification of the present invention is disclosed in my pending application,-Serial No. 228,336, filed October 24, A1927.

What I regard as new, and desire to secure by Letters Patent, is:

1.A hand-carried spraying-device comprising a motor having its front end provided with a removable cap-plate having a compressor-cylinder formed integrally therewith and having air outlet-passages around the cylinder, a rotor mounted in said cylinder and actuated `by the armature of the motor, a fan disposed back of said cap-plate and actuated by the armature of the motor, a

nozzle rigidly connected with the compressor, a container depending from said nozzle, and a handle having its upper portion secured to the lower side of the motor-compressor unit and equipped with a switch-device controlling the motor, said switch-device having a linger-piece located at the upper front portion of the handle.

hand-carried sprayingdevice comprising an electr-ic motor having a horizontal axis and provided at 'itsf front end with a removable cap-plate, having a compressorcylinder forme integrally therewith and having air'outlet-passa es around the cylmder, a rotor mounted 1n said cylinder` and actuated by the armature of said motor, a fan disposed back of said cap-plate and actuated b rigidly connected with the compressor 'and equipped with a dependin container-supfportlng member anda li ui tube depending from said member, a han le having its u per end rigidly connected with the lower si e of the motor casing, a switch mounted in'the upper ortion of said handle, a forwardly projecting trigger mounted in the upper portion of said handle controllin ductors extending through the handle and from the upper portion thereof into the motor casing, said circuit being controlled by said switc 3. A device as specified in claim 2, in which- Asaid switch is equl ped with a spring which servesto break' t e circuit when pressure WOLFGANG HERMANN l mensen' the armature of sald motor, a nozzle said switch, and a motor-controlling circuit having con- 

